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1994-01-02
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PB Plus+ Compiler
Computing Systems Design, Inc.
4437 Ormond Trace
Marietta, GA 30066
CompuServe ID 72701,155
24 Hour FAX (404) 926-9565
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PB Plus+ is an extension of PowerBatch, adding several powerful commands
for the advanced developer. PB Plus+ gives the developer the capability to
create sophisticated programs with relative ease. Below is a list of
commands included in PB Plus+ in addition to all the commands in
PowerBatch.
ASCII File I/O
~~~~~~~~~~~~~~
Four file commands READFILE, WRITEFILE, APPENDFILE, and CLOSEFILE provide
the capability to manipulate up 8 files at any one time. Files are
automatically opened and closed at the appropriate time. (You can issue a
READFILE command immediately following a WRITEFILE command and the file
you were writing to will automatically be closed as output, re-opened as
input and positioned at the beginning of the file.) With the APPENDFILE
command, you can add to an existing file. All files are automatically
closed for you at the successful completion of your program.
Dynamic Arrays
~~~~~~~~~~~~~~
Array handling was never easier. Define an array by giving the APPROXIMATE
length of each entry in the array and the APPROXIMATE number of elements in
the array. PB Plus+ will allocate enough memory in the heap to contains the
number of bytes needed to contain these entries. Each array element written
consumes only as much space as the length of the element! If you define an
array containing 25 entries each 40 characters long, 1000 bytes of memory
would be allocated for your array. Since each entry takes only as much
space as is necessary, you could write 100 entries that were only 10
characters each!! No matter that you told me you would have only 25
entries, it is the total amount of memory used that counts.
It get even better. Suppose you underestimate the size needed for the
array. No worry. PB Plus+ will simply allocate additional memory for your
array and you continue writing as long as heap memory is available! You
could easily write several thousand entries in your array without crashing
the program.
Subroutines
~~~~~~~~~~~
True subroutine execution up to 32 levels deep. (You can PERFORM within a
PERFORM within a PERFORM... up to 32 levels). A subroutine begins with a
label and ends with an EXIT command. When the exit command is reached, the
program returns to the statement immediately following your PERFORM
statement.
Screen Saves
~~~~~~~~~~~~
Just the thing that is needed for true "menu popping". Execute the SAVEBOX
command identifying the upper row and column and the lower row and column
boundaries and PB Plus+will allocate memory on the heap to save all the
data, color attributes, and cursor location within the defined box. Draw
your menu on the screen, get the input from the user, and issue the RESTBOX
command. PB Plus+ will find your saved data and restore the screen in a
flash. Up to 16 saved areas may be active at any one time. Multiple
executions of the RESTBOX command will "pop" the screen back for you in
sequence.
Program Swapping
~~~~~~~~~~~~~~~~
What a powerful command! The swap command is so simple... either SWAP ON or
SWAP OFF. If SWAP is ON, any external program or DOS command you execute
will cause your PB Plus+ program to be "swapped" out of active memory to
give the external process the maximum amount of memory available. When the
external command is finished, your PB Plus+ program takes up right where it
left off!
Here's what happens without you even having to worry. PB Plus+ searches
your system for either EMS, XMS, or a hard drive (in that order). Your PB
Plus+ program is swapped to one of these available resources, leaving
behind less then 4k to handle the swapping back in of your program after
the external command is finished. Swap to one of the memory resources (EMS,
or XMS) and this occurs in the blink of any eye. Even swapping to a hard
drive takes approx 2 seconds.
PB Plus+ is a solid bug free system that is already in use by several
thousand users. It comes with printed documentation on the diskette size of
your choice. If you haven't run PLUSDEMO.EXE located on your PowerBat disk,
run this demonstration to see the power and flexibility of PB Plus+.